Either through the use of clones, or Minato teleporting him to safety. Maybe even both. Minato can easily look after Kakashi while he tags Ay, as his top speed becomes of little trouble to Minato who after seeing it only once, can react to indicatively easily based on his facial expression [
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]. I also don't believe Ay can maintain this speed for too long, as his chakra rises to tailed beast levels [
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] in order to achieve V2 speed. Ay has never been shown to maintain this speed for extensive periods of time, and it's pretty obvious he can't. He'd have to revert back to V1 as he did repeatedly with Madara allowing for a swift capitalisation. It's easy to track tags when Minato had them spread in an enclosed area, but this won't be the case when fighting two top tier speedsters. They'd be spread out over a much greater distance.